OpenRaiser/Intern-Atlas huggingface dataset:
Sysml Knowledge base for Designing Dependable Complex System
Venue: arXiv cs.SE 2012
Year: 2012

The work presented in this paper is part of a proposed framework as complete and rigorous as possible for the design of complex systems. The methodological framework used is System Engineering, which is a methodological approach to control the design of complex systems. The practices of this approach are transcribed in standards, realized by methods and supported by tools. In our case, the standard EIA-632 was adopted. Specifically, to deal with the dependability of these complex systems and to improve the processes dealing with dependability, we have defined a global approach. This approach incorporates the consideration of dependability in system engineering processes. The work presented in this paper supports and complements the overall approach: it is the proposal of an information model based on the SysML language, allowing the requirements management, including safety requirements
Combined Human, Antenna Orientation in Elevation Direction and Ground Effect on RSSI in Wireless Sensor Networks
Venue: arXiv cs.NI 2012
Year: 2012

In this paper, we experimentally investigate the combined effect of human, antenna orientation in elevation direction and the ground effect on the Received Signal Strength Indicator (RSSI) parameter in the Wireless Sensor Network (WSN). In experiment, we use MICAz motes and consider different scenarios where antenna of the transmitter node is tilted in elevation direction. The motes were placed on the ground to take into account the ground effect on the RSSI. The effect of one, two and four persons on the RSSI is recorded. For one and two persons, different walking paces e.g. slow, medium and fast pace, are analysed. However, in case of four persons, random movement is carried out between the pair of motes. The experimental results show that some antenna orientation angles have drastic effect on the RSSI, even without any human activity. The fluctuation count and range of RSSI in different scenarios with same walking pace are completely different. Therefore, an efficient human activity algorithm is need that effectively takes into count the antenna elevation and other parameters to accurately detect the human activity in the WSN deployment region.
Truthy: Enabling the Study of Online Social Networks
Venue: arXiv cs.SI 2012
Year: 2012

The broad adoption of online social networking platforms has made it possible to study communication networks at an unprecedented scale. Digital trace data can be compiled into large data sets of online discourse. However, it is a challenge to collect, store, filter, and analyze large amounts of data, even by experts in the computational sciences. Here we describe our recent extensions to Truthy, a system that collects Twitter data to analyze discourse in near real-time. We introduce several interactive visualizations and analytical tools with the goal of enabling citizens, journalists, and researchers to understand and study online social networks at multiple scales.
Data Mapping for Unreliable Memories
Venue: arXiv cs.IT 2012
Year: 2012

Future digital signal processing (DSP) systems must provide robustness on algorithm and application level to the presence of reliability issues that come along with corresponding implementations in modern semiconductor process technologies. In this paper, we address this issue by investigating the impact of unreliable memories on general DSP systems. In particular, we propose a novel framework to characterize the effects of unreliable memories, which enables us to devise novel methods to mitigate the associated performance loss. We propose to deploy specifically designed data representations, which have the capability of substantially improving the system reliability compared to that realized by conventional data representations used in digital integrated circuits, such as 2s complement or sign-magnitude number formats. To demonstrate the efficacy of the proposed framework, we analyze the impact of unreliable memories on coded communication systems, and we show that the deployment of optimized data representations substantially improves the error-rate performance of such systems.
Maximally Informative Observables and Categorical Perception
Venue: arXiv cs.LG 2012
Year: 2012

We formulate the problem of perception in the framework of information theory, and prove that categorical perception is equivalent to the existence of an observable that has the maximum possible information on the target of perception. We call such an observable maximally informative. Regardless whether categorical perception is real, maximally informative observables can form the basis of a theory of perception. We conclude with the implications of such a theory for the problem of speech perception.
Recognition of Logically Related Regions Based Heap Abstraction
Venue: arXiv cs.LO 2012
Year: 2012

This paper presents a novel set of algorithms for heap abstraction, identifying logically related regions of the heap. The targeted regions include objects that are part of the same component structure (recursive data structure). The result of the technique outlined in this paper has the form of a compact normal form (an abstract model) that boosts the efficiency of the static analysis via speeding its convergence. The result of heap abstraction, together with some properties of data structures, can be used to enable program optimizations like static deallocation, pool allocation, region-based garbage collection, and object co-location. More precisely, this paper proposes algorithms for abstracting heap components with the layout of a singly linked list, a binary tree, a cycle, and a directed acyclic graph. The termination and correctness of these algorithms are studied in the paper. Towards presenting the algorithms the paper also presents concrete and abstract models for heap representations.
NP-Hardness of optimizing the sum of Rational Linear Functions over an Asymptotic-Linear-Program
Venue: arXiv cs.CC 2012
Year: 2012

We convert, within polynomial-time and sequential processing, an NP-Complete Problem into a real-variable problem of minimizing a sum of Rational Linear Functions constrained by an Asymptotic-Linear-Program. The coefficients and constants in the real-variable problem are 0, 1, -1, K, or -K, where K is the time parameter that tends to positive infinity. The number of variables, constraints, and rational linear functions in the objective, of the real-variable problem is bounded by a polynomial function of the size of the NP-Complete Problem. The NP-Complete Problem has a feasible solution, if-and-only-if, the real-variable problem has a feasible optimal objective equal to zero. We thus show the strong NP-hardness of this real-variable optimization problem.
Guadalupe: a browser design for heterogeneous hardware
Venue: arXiv cs.OH 2012
Year: 2012

Mobile systems are embracing heterogeneous architectures by getting more types of cores and more specialized cores, which allows applications to be faster and more efficient. We aim at exploiting the hardware heterogeneity from the browser without requiring any changes to either the OS or the web applications. Our design, Guadalupe, can use hardware processing units with different degrees of capability for matched browser services. It starts with a weak hardware unit, determines if and when a strong unit is needed, and seamlessly migrates to the strong one when necessary. Guadalupe not only makes more computing resources available to mobile web browsing but also improves its energy proportionality. Based on Chrome for Android and TI OMAP4, We provide a prototype browser implementation for resource loading and rendering. Compared to Chrome for Android, we show that Guadalupe browser for rendering can increase other 3D application's frame rate by up to 767% and save 4.7% of the entire system's energy consumption. More importantly, by using the two cases, we demonstrate that Guadalupe creates the great opportunity for many browser services to get better resource utilization and energy proportionality by exploiting hardware heterogeneity.
FReD: Automated Debugging via Binary Search through a Process Lifetime
Venue: arXiv cs.SE 2012
Year: 2012

Reversible debuggers have been developed at least since 1970. Such a feature is useful when the cause of a bug is close in time to the bug manifestation. When the cause is far back in time, one resorts to setting appropriate breakpoints in the debugger and beginning a new debugging session. For these cases when the cause of a bug is far in time from its manifestation, bug diagnosis requires a series of debugging sessions with which to narrow down the cause of the bug. For such "difficult" bugs, this work presents an automated tool to search through the process lifetime and locate the cause. As an example, the bug could be related to a program invariant failing. A binary search through the process lifetime suffices, since the invariant expression is true at the beginning of the program execution, and false when the bug is encountered. An algorithm for such a binary search is presented within the FReD (Fast Reversible Debugger) software. It is based on the ability to checkpoint, restart and deterministically replay the multiple processes of a debugging session. It is based on GDB (a debugger), DMTCP (for checkpoint-restart), and a custom deterministic record-replay plugin for DMTCP. FReD supports complex, real-world multithreaded programs, such as MySQL and Firefox. Further, the binary search is robust. It operates on multi-threaded programs, and takes advantage of multi-core architectures during replay.
A Comparison between CODYRUN and TRNSYS, simulation models for thermal buildings behaviour
Venue: arXiv cs.CE 2012
Year: 2012

Simulation codes of thermal behaviour could significantly improve housing construction design. Among the existing software, CODYRUN and TRNSYS are calculations codes of different conceptions. CODYRUN is exclusively dedicated to housing thermal behaviour, whereas TRNSYS is more generally used on any thermal system. The purpose of this article is to compare these two instruments in two different conditions . We will first modelize a mono-zone test cell, and analyse the results by means of signal treatment methods. Then, we will modelize a real case of multi-zone housing, representative of housing in wet tropical climates. We could so evaluate influences of meteorological and building description data on model errors.
Heat transfer in buildings : application to air solar heating and Trombe wall design
Venue: arXiv cs.CE 2012
Year: 2012

The aim of this paper is to briefly recall heat transfer modes and explain their integration within a software dedicated to building simulation (CODYRUN). Detailed elements of the validation of this software are presented and two applications are finally discussed. One concerns the modeling of a flat plate air collector and the second focuses on the modeling of Trombe solar walls. In each case, detailed modeling of heat transfer allows precise understanding of thermal and energetic behavior of the studied structures. Recent decades have seen a proliferation of tools for building thermal simulation. These applications cover a wide spectrum from very simplified steady state models to dynamic simulation ones, including computational fluid dynamics modules (Clarke, 2001). These tools are widely available in design offices and engineering firms. They are often used for the design of HVAC systems and still subject to detailed research, particularly with respect to the integration of new fields (specific insulation materials, lighting, pollutants transport, etc.). Available from: http://www.intechopen.com/books/evaporation-condensation-and-heat-transfer/heat-transfer-in-buildings-application-to-solar-air-collector-and-trombe-wall-design
A multimodel approach to building thermal simulation for design and research purposes
Venue: arXiv cs.CE 2012
Year: 2012

The designers pre-occupation to reduce energy consumption and to achieve better thermal ambience levels, has favoured the setting up of numerous building thermal dynamic simulation programs. The progress in the modelling of phenomenas and its transfer into the professional field has resulted in various numerical approaches ranging from softwares dedicated to architects for design use to tools for laboratory use by the expert thermal researcher. This analysis shows that each approach tends to fulfil the specific needs of a certain kind of manipulator only, in the building conception process. Our objective is notably different as it is a tool which can be used from the very initial stage of a construction project, to the energy audit for the existing building. In each of these cases, the objective results, the precision advocated and the time delay of the results are different parameters which call for a multiple model approach of the building system
Étude comparée de quatre logiciels de gestion de références bibliographiques libres ou gratuits
Venue: arXiv cs.IR 2012
Year: 2012

This article is the result of the analysis of various bibliographic reference management tools, especially those that are free. The use of editorial tools by bibliographic editors has evolved rapidly since 2007. But, until recently, free software has fallen short when it comes to ergonomics or use. The functional and technical panorama offered by free software is the result of the comparison of JabRef, Mendeley Desktop, BibDesk and Zotero software undertaken in January 2012 by two research professors affiliated with the Institut national français des techniques de la documentation (INTD).
Characterizing Multivariate Information Flows
Venue: arXiv cs.IT 2012
Year: 2012

One of the crucial steps in scientific studies is to specify dependent relationships among factors in a system of interest. Given little knowledge of a system, can we characterize the underlying dependent relationships through observation of its temporal behaviors? In multivariate systems, there are potentially many possible dependent structures confusable with each other, and it may cause false detection of illusory dependency between unrelated factors. The present study proposes a new information-theoretic measure with consideration to such potential multivariate relationships. The proposed measure, called multivariate transfer entropy, is an extension of transfer entropy, a measure of temporal predictability. In the simulations and empirical studies, we demonstrated that the proposed measure characterized the latent dependent relationships in unknown dynamical systems more accurately than its alternative measure.
Spin foam with topologically encoded tetrad on trivalent spin networks
Venue: arXiv cs.IT 2012
Year: 2012

We explore discrete approaches in LQG where all fields, the gravitational tetrad, and the matter and energy fields, are encoded implicitly in a graph instead of being additional data. Our graph should therefore be richer than a simple simplicial decomposition. It has to embed geometrical information and the standard model. We start from Lisi's model. We build a trivalent graph which is an F4 lattice of 48-valent supernodes, reduced as trivalent subgraphs, and topologically encoding data. We show it is a solution for EFE with no matter. We define bosons and half-fermions in two dual basis. They are encoded by bit exchange in supernodes, operated by Pachner 2-2 move, and rest state can be restored thanks to information redundancy. Despite its 4 dimensional nature, our graph is a trivalent spin network, and its history is a pentavalent spin foam.
Personality wireless sensor networks (PWSNs)
Venue: arXiv cs.NI 2012
Year: 2012

In recent years, WSNs are garnering lot of interest from research community because of their unique characteristics and potential for enormous range of applications. Envision for new class of applications are being emerged such as human augmentation, enhancing social interaction etc. Misunderstanding or misinterpretation of behaviors from individuals leads to social conflicts. There are various theories that classify people into different personality types. Most of the existing theories rely on questionnaires, which is highly unreliable. Anyone can lead such theories in practice to incorrect classification intentionally or unintentionally. The objective of this research is to investigate existing solutions and propose a basic infrastructure for an automated context-aware psychological classification based on different parameters. The idea is to use wearable sensors to sense and measure various human body parameters (i.e. body temperature, blood pressure, perspiration, brain impulses etc) that coerce human psychological condition. The data collected from these parameters is transformed in to information, to determine personality type, mood and psychological condition of interacting parties. This information is shared among counterparts to better understand each other in order to avoid potential conflicting situations. We believe that it will help peoples understand each other, improve their quality of life and minimize possible conflicting situations.
Black box modelling of HVAC system : improving the performances of neural networks
Venue: arXiv cs.NE 2012
Year: 2012

This paper deals with neural networks modelling of HVAC systems. In order to increase the neural networks performances, a method based on sensitivity analysis is applied. The same technique is also used to compute the relevance of each input. To avoid the prediction errors in dry coil conditions, a metamodel for each capacity is derived from the neural networks. The regression coefficients of the polynomial forms are identified through the use of spectral analysis. These methods based on sensitivity and spectral analysis lead to an optimized neural network model, as regard to its architecture and predictions.
A Hybrid Approach for Optimizing Planar Triangular Meshes
Venue: arXiv cs.CG 2012
Year: 2012

Modified Direct Method (MDM) is an iterative scheme based on Jacobi iterations for smoothing planar meshes [4]. The basic idea behind MDM is to make any triangular element be as close to an equilateral triangle as possible. Basedon the MDM, a length-weighted MDM is proposed and then combined with edge swapping. In length-weighted MDM, weights of each neighboring node of a smoothed node are determined by the length of its opposite edge. Also, the MDM, Laplacian smoothing and length-weighted MDM are all combined with edge swapping, and then implemented and compared on both structured and unstructured triangular meshes. Examples show that length-weighted MDM is better than the MDM and Laplacian smoothing for structured mesh but worse for unstructured mesh. The hybrid approach of combining length-weighted MDM and edge swapping is much better and can obtain more even optimized meshes than other two hybrid approaches.
Discrete Surface Modeling Based on Google Earth: A Case Study
Venue: arXiv cs.GR 2012
Year: 2012

Google Earth (GE) has become a powerful tool for geological, geophysical and geographical modeling; yet GE can be accepted to acquire elevation data of terrain. In this paper, we present a real study case of building the discrete surface model (DSM) at Haut-Barr Castle in France based on the elevation data of terrain points extracted from GE using the COM API. We first locate the position of Haut-Barr Castle and determine the region of the study area, then extract elevation data of terrain at Haut-Barr, and thirdly create a planar triangular mesh that covers the study area and finally generate the desired DSM by calculating the elevation of vertices in the planar mesh via interpolating with Universal Kriging (UK) and Inverse Distance Weighting (IDW). The generated DSM can reflect the features of the ground surface at Haut-Barr well, and can be used for constructingthe Sealed Engineering Geological Model (SEGM) in further step.
Transfer Learning Using Logistic Regression in Credit Scoring
Venue: arXiv cs.LG 2012
Year: 2012

The credit scoring risk management is a fast growing field due to consumer's credit requests. Credit requests, of new and existing customers, are often evaluated by classical discrimination rules based on customers information. However, these kinds of strategies have serious limits and don't take into account the characteristics difference between current customers and the future ones. The aim of this paper is to measure credit worthiness for non customers borrowers and to model potential risk given a heterogeneous population formed by borrowers customers of the bank and others who are not. We hold on previous works done in generalized gaussian discrimination and transpose them into the logistic model to bring out efficient discrimination rules for non customers' subpopulation. Therefore we obtain several simple models of connection between parameters of both logistic models associated respectively to the two subpopulations. The German credit data set is selected to experiment and to compare these models. Experimental results show that the use of links between the two subpopulations improve the classification accuracy for the new loan applicants.
Secluded Connectivity Problems
Venue: arXiv cs.DS 2012
Year: 2012

Consider a setting where possibly sensitive information sent over a path in a network is visible to every {neighbor} of the path, i.e., every neighbor of some node on the path, thus including the nodes on the path itself. The exposure of a path $P$ can be measured as the number of nodes adjacent to it, denoted by $N[P]$. A path is said to be secluded if its exposure is small. A similar measure can be applied to other connected subgraphs, such as Steiner trees connecting a given set of terminals. Such subgraphs may be relevant due to considerations of privacy, security or revenue maximization. This paper considers problems related to minimum exposure connectivity structures such as paths and Steiner trees. It is shown that on unweighted undirected $n$-node graphs, the problem of finding the minimum exposure path connecting a given pair of vertices is strongly inapproximable, i.e., hard to approximate within a factor of $O(2^{\log^{1-ε}n})$ for any $ε>0$ (under an appropriate complexity assumption), but is approximable with ratio $\sqrtΔ+3$, where $Δ$ is the maximum degree in the graph. One of our main results concerns the class of bounded-degree graphs, which is shown to exhibit the following interesting dichotomy. On the one hand, the minimum exposure path problem is NP-hard on node-weighted or directed bounded-degree graphs (even when the maximum degree is 4). On the other hand, we present a polynomial algorithm (based on a nontrivial dynamic program) for the problem on unweighted undirected bounded-degree graphs. Likewise, the problem is shown to be polynomial also for the class of (weighted or unweighted) bounded-treewidth graphs.
The Buffered π-Calculus: A Model for Concurrent Languages
Venue: arXiv cs.LO 2012
Year: 2012

Message-passing based concurrent languages are widely used in developing large distributed and coordination systems. This paper presents the buffered $π$-calculus --- a variant of the $π$-calculus where channel names are classified into buffered and unbuffered: communication along buffered channels is asynchronous, and remains synchronous along unbuffered channels. We show that the buffered $π$-calculus can be fully simulated in the polyadic $π$-calculus with respect to strong bisimulation. In contrast to the $π$-calculus which is hard to use in practice, the new language enables easy and clear modeling of practical concurrent languages. We encode two real-world concurrent languages in the buffered $π$-calculus: the (core) Go language and the (Core) Erlang. Both encodings are fully abstract with respect to weak bisimulations.